JP2010162377A - Positive airway pressure system for treatment of sleeping disorder in patient - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for treatment of patient's sleeping disorder dealing with a state of patient's discomfort during wakefulness. <P>SOLUTION: Described is a positive airway pressure system for treatment of a sleeping disorder in a patient. The system includes a generator, a sensor, and a processing arrangement. The generator supplies airflow and applies pressure to an airway of a patient. The sensor measures data corresponding to patient's breathing patterns. The processing arrangement analyzes the breathing patterns to determine whether the breathing patterns are indicative of at least one of the following patient's states: (i) a regular breathing state, (ii) a sleep disorder breathing state, (iii) a REM sleep state, and (iv) a troubled wakefulness state. The processing arrangement adjusts the applied pressure as a function of the patient's state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to medical treatment systems, and more particularly to a system for treating sleep disorders.

  Obstructive sleep apnea syndrome (OSAS) is a well-known disorder that affects 1 to 5% of adults. OSAS is one of the most common causes of excessive sleepiness during the day. OSAS occurs most often in obese men and is one of the most common reasons to refer to a sleep disorder clinic.

  OSAS is associated with many conditions that have an anatomical or functional stenosis of the patient's upper airway and is characterized by intermittent obstruction of the upper airway that occurs during sleep. This obstruction results in respiratory disturbances ranging from complete lack of airflow (apnea) to significant obstruction with or without reduced airflow (hypopnea and snoring), despite continuous breathing exercise. The morbidity of this syndrome is due to decreased oxygen in the blood, excessive carbonic acid, bradycardia, and sleep interruptions associated with apnea and waking from sleep.

  The pathophysiology of OSAS has not been fully elucidated. However, it is now well known that obstruction of the upper respiratory tract during sleep is due in part to collapsible behavior of the upper glottis in the respiratory airway due to negative intraluminal pressure generated by inspiratory motion. It has been. Thus, in OSAS patients, the upper airway during sleep operates almost as a Staring register (ie, the airflow is limited to a fixed value regardless of drive (inspiratory) pressure). In so doing, partial or complete airway stenosis occurs with the loss of airway sound that is characteristic of sleep onset and excessive in OSAS.

  Since 1981, positive airway pressure (PAP) applied by a tight nasal mask worn during sleep has developed as the most effective treatment for OSAS and is currently the standard of care. With the availability of non-invasive treatment modalities, OSAS has become widely known, and many patients have emerged who may have previously avoided treatment because of fear of tracheostomy. Increasing the comfort of the PAP system is a major goal of research aimed at improving patient flexibility in its treatment.

  PAP treatment is obstructive sleep apnea, upper airway resistance syndrome, snoring, excessive increase in upper airway stenosis induced by sleep, and inappropriate non-physiological obstruction of airflow due to inappropriate stenosis of upper airway segments It has become the mainstay of treatment in obstructive sleep irregular breathing (OSDB), including all conditions that produce. Such stenosis generally occurs whenever the pressure in the constrictible portion of the airway falls below a level defined as “critical tissue pressure” in the surrounding wall. PAP treatment is performed to always maintain the pressure in the constrictible portion of the airway at or above the critical tissue pressure. Conventional PAP treatment has been performed by raising the pressure delivered to the patient's airway to a level higher than the critical tissue pressure while the patient is wearing the device. In general, the need for PAP treatment is limited to sleep. However, the conventional PAP treatment does not consider the sleep / wake state, and the conventional PAP system unnecessarily pressurizes even when the patient is awake. The applied pressure is a pressure based on a constant-pressure or measurement taken for each breath with respect to the need for treatment (breath-by-breath determination). Due to feedback from various signals indicating the need for PAP treatment due to airway stenosis, different methods for measuring minimum pressure can be used for pathological events (eg apnea, hypopnea, other indications of high airway resistance). Has developed based on perceptions of evidence.

  Despite the success of conventional PAP treatment, limitations in the use of conventional PAP systems still exist rooted in the pressures required to eliminate mask discomfort and apnea. In particular, patients often complain of discomfort due to the high pressure applied when awake. For example, using a “ramp” system, the patient operatively delays the onset of pressurization, but this system is automatic for awakening the patient at night unless the patient himself activates at the push of a button. Does not respond.

  The patient's discomfort during arousal often accompanies a change from a regular breathing pattern (eg, a nearly constant breath size and frequency) to an irregular breathing pattern. Such irregular patterns (e.g. single deep breaths, short interruptions, changes in the waveform of the breathing flow that do not change in the regular pattern) are accepted to examine only the airflow tracing, Often occurs when the patient is suffering from the PAP system.

  Some conventional PAP systems use algorithms that continuously and automatically titrate the applied pressure. These algorithms rely on detecting evidence of airway narrowing from the respiratory signal. However, conventional PAP system algorithms have certain limitations. For example, if the subject is awake, an irregular pattern of breathing occurs; if the subject feels anxious, an irregular pattern of breathing is more likely to occur and the respiratory signal that calculates the applied pressure Hinder processing.

  An object of the present invention is to provide a system for treating a sleep disorder of a patient, which can cope with a state of awakening in which the patient has discomfort.

  A positive airway pressure system for treating a patient's sleep disorder is described below. The system includes a generator, a sensor, and a processing device. The generator provides an air flow and applies pressure to the patient's airway. The sensor measures data corresponding to the patient's breathing pattern. The processor analyzes the breathing pattern, and the breathing pattern is the patient's next state: (i) a state of regular breathing, (ii) a state of breathing causing sleep disturbances, (iii) Determine whether it shows at least one of: REM sleep state, or (iv) problematic wakefulness. The processor adjusts the applied pressure in relation to the patient's condition. Regular breathing conditions include a state where the patient is asleep from apnea and a state where he is relaxed and awake, but in a troubled arousal state, the patient is anxious or uncomfortable. Those skilled in the art will understand that this causes irregular breathing.

  The present invention is also a positive airway pressure system for treating a patient's sleep disorder, which supplies airflow to the patient's airway and applies pressure, and data corresponding to the patient's breathing pattern. A sensor that measures the respiratory pattern of the patient, and the detected respiratory pattern is (i) a state in which the patient is breathing regularly, (ii) a state in which the patient is experiencing sleep disturbances The status, (iii) the patient is in REM sleep state, and (iv) whether the patient exhibits one of the unpleasant wakefulness and added in relation to the patient's condition And a processing device that adjusts the pressure, and when the patient's breathing pattern indicates a state of (iv), the processing device sets a target pressure value, and the pressure applied by controlling the generator is Target pressure And adjusting so as to approach the.

  The present invention is also a system for monitoring patient breathing, wherein a sensor for measuring data corresponding to the patient breathing pattern and the patient breathing pattern indicate an arousal state in which the patient feels uncomfortable. And a processing device for determining whether or not.

The figure which shows one Example of the system by this invention. 2 shows an embodiment of the method according to the invention using the system shown in FIG. FIG. 5 shows an airflow waveform in a normal arousal state (eg, not an anxiety state) of a patient using a system according to the present invention. The figure which shows the waveform of the airflow in a patient's normal sleep state. The figure which shows the waveform of the airflow from the patient in sleep which shows the upper airway pressure resistance which rises, and a respiratory fall. The figure which shows the waveform of the airflow from the patient in sleep which shows a repetitive obstructive apnea state. The figure which shows the waveform of the airflow from the patient which shows the period of the arousal state which becomes a problem. The figure which shows the waveform of the airflow from a patient which shows the period of the REM sleep accompanied by the irregular respiration by a patient's phasic REM.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate and explain embodiments of the invention together with a detailed description of the invention.
FIG. 1 shows an exemplary embodiment of a system 1 according to the invention. The system 1 includes a mask 20 connected via a tube 21 that receives an airflow having a specific pressure from an airflow generator 22. The amount of pressure delivered to the patient is altered in relation to the patient's symptoms. Such amount of pressure may be measured using PAP treatment methods according to the prior art.

  Mask 20 covers the patient's nose and / or mouth. A conventional flow sensor 23 is connected to the tube 21. The sensor 23 detects the air flow to / from the patient and / or the pressure supplied to the patient from the generator 22. The sensor 23 may be installed inside or outside the generator 22. A signal corresponding to the air flow rate and / or pressure is supplied to the processing device 24 for processing. The processing device 24 outputs a signal to the conventional flow rate control device 25 to control the pressure applied to the flow tube 21 by the airflow generator 22. Instead of controlling the airflow from the airflow generator 22 by operating a different flow controller 25 for a particular type of airflow generator that can be used as the airflow generator 22, the processing device 24 causes the airflow generator 22 to operate. One skilled in the art will recognize that it may be directly controlled.

  The system 1 may also include a continuous leak port or other ventilation device 28. The ventilator 28 diverts the gas contained in the airflow discharged by the patient from the incoming airflow to prevent re-inhalation of the discharged gas.

  FIG. 2 shows an exemplary embodiment of the method according to the invention. In step 202, the patient wears the mask 20 on the face, turns on the airflow generator 22, the flow control device 25, and the processing device 24, and activates the system 1.

  In step 204, the system 1 begins monitoring the patient's breathing pattern in real time. This monitoring procedure is performed by the processing device 24, and pre-stored patient data is updated with the latest data regarding the airflow to and from the patient and / or the applied pressure provided by the flow sensor 23. Used in conjunction with.

  In the monitoring procedure, the processing device 24 may be updated with the patient's current state (eg, the patient is sleeping, breathing regularly while awake, or breathing irregularly due to pain or anxiety while awake. Measurement). Such measurements are made based on a number of different measurements. For example, the processing device 24 can analyze the patient's heart rate, blood pressure, brain waves, respiratory pattern, and the like when measuring the patient's condition.

  There are a number of characteristics of patient breathing patterns that can be considered when making such measurements. 3 and 4 are breathing patterns showing that the patient is taking regular and stable breathing at rest in the PAP treatment. FIG. 3 shows a stable arousal state (the patient feels neither anxiety nor pain). FIG. 4 shows a stable respiratory cycle during sleep, during which the patient is correctly treated with PAP therapy. In either case, the applied pressure is supplied without compromising comfort. In addition, there is a cycle of breathing that causes sleep disturbance, and PAP therapy must be performed in this cycle. Indications of breathing that cause sleep disorders include apnea (eg, a state of zero airflow that is longer than 8-10 seconds alternates with deep breathing), hypopnea (eg, airflow periodically decreases, 10 Or a period in which the shape of the signal changes intermittently and periodically (eg, characterized by a flat waveform and terminated by breathing in a normal shape).

  In contrast, the following typical features suggest that the patient is awake and feels anxiety and distress: totally mouth breathing (eg, detecting airflow from the patient's nose) No signal from flow sensor 23); abnormal deep breathing with changing expiration time; irregular intervals between breaths (but not periodic apnea states indicating sleep and high pressure needs, etc.) ). FIG. 7 shows such a problematic wakefulness cycle, where the breathing pattern in that cycle is an irregular change in respiratory volume and / or frequency, and / or the patient is awake and feels anxious or uncomfortable. There is a feature of showing an irregular change in the waveform indicating the trajectory of the patient's airflow. However, there are no periodic changes in respiratory volume (eg, periodic irregularities) as seen when apnea or hypopnea occur. One way to increase patient comfort is to reduce the pressure applied when not needed. Patients with obstructive sleep apnea do not require any pressure when awake. Therefore, reducing the pressure applied to the mask during irregular breathing should improve patient comfort until the patient falls asleep (eg, this restores regularity and periodicity). It is different from regular obstruction and elevated upper airway resistance, which are easily recognized as apnea or hypopnea).

  The above breathing pattern is different from the gradual change in breathing rate and timing of expiration as seen in other breathing forms such as breathing volume and other forms of obstructive apnea. FIG. 5 shows a breathing pattern of a patient undergoing PAP treatment, and an increase in upper airway resistance and a decrease in breathing occur during sleep. FIG. 6 shows a breathing pattern corresponding to repetitive obstructive apnea. In both figures, changes in respiratory volume and frequency occur slowly and are repetitive and periodic (eg, regularly exhibit irregularities). In such a cycle, pressurization is required or the applied pressure must be increased, but there are no signs of pain to the patient. Therefore, the applied pressure must not be reduced.

  FIG. 8 shows the REM sleep period. Such a sleep period, for example, appears every 90 minutes for 10-30 minutes in normal sleep, and the breathing pattern is often characterized by irregular breathing. This breathing pattern is thought to represent an exception to irregularities that indicate an arousal in anxiety. However, when performing such breathing, the patient is asleep and the applied pressure must be maintained (ie, should not be reduced as during arousal). The irregularity seen during REM sleep is different from the irregularity seen at waking in several important parameters. The respiratory patterns associated with this REM sleep include, for example, lack of deep breathing (especially after interruption), generally high respiratory rate and low air flow, and accumulation of shallow breaths. Since the pattern of the respiratory airflow signal is different from the pattern seen at the time of awakening, it is possible to distinguish such a state and change the applied pressure.

  The processing device 24 collects and records data for each patient. Such data may be collected and input manually by a technician or may be performed automatically by the processing device 24. For example, the technician may monitor the patient's breathing and at the same time determine whether the patient is awake. Next, when the patient falls asleep, the technician records the breathing pattern of the sleeping patient and can be used by the processor 24 later to use this data to determine whether the patient is awake. it can. Once a database is built that records the patient's respiratory characteristics, measurements about the patient's wakefulness are made very accurately.

  In step 206, the processor 24 measures whether there is a change in the patient's condition. For example, the processor 24 measures whether the patient was asleep but is now awake, or whether the patient was awake but is now asleep. If there is no change, the processing device 24 continues to monitor.

  If there is a change in the patient's condition, the processor 24 adjusts the pressure corresponding to the patient's current condition (step 208). For example, if the patient is awake and the respiratory pattern indicates a problematic wakeful cycle as shown in FIG. 7, the processor 24 reduces the pressure supplied to the patient during that cycle. This reduction completely removes the applied pressure (i.e., reduces airflow to a level where the airflow generator 22 does not supply a net pressure to the patient wearing the mask, but reduces the CO2 A minimum air flow is maintained through the circuit to the ventilator 28 to prevent an increase). Alternatively, a partial reduction is made (ie, the airflow generator 22 produces only the airflow necessary to maintain the reduced amount of air pressure generated while the patient is sleeping).

  On the other hand, if the patient has fallen asleep, the processing device 24 instructs the flow control device 25 to increase the pressure to a level that can be applied while the patient is sleeping. For example, this is indicated when the patient breathing pattern changes from the pattern shown in FIG. 7 to the pattern shown in FIG. In such a case, the processing device 24 must increase the pressure. From that point on, this increased pressure must not be reduced until one of the predetermined plurality of breathing patterns is detected. For example, the processor 24 must maintain at least the same pressure, or increase the pressure if the patient's breathing pattern indicates the occurrence of elevated upper airway resistance or hypopnea as shown in FIG. Is desirable. Also, the pressure must be maintained at least at the same value, or it is desirable to increase the pressure if the patient's breathing pattern exhibits repetitive obstructive apnea as shown in FIG. Alternatively, if the patient is taking irregular breaths suggesting that they are in REM sleep, the patient is sleeping and the applied pressure must be maintained at a level similar to other sleep cycles ( That is, it must not be reduced as well as arousal).

  In step 210, the processing device 24 determines whether an instruction to release the system 1 is given. When such an instruction is given (for example, when the patient presses the designated button or the set time has passed), the system 1 stops and completes all monitoring and airflow generation operations. To do. Alternatively, the system 1 continues to monitor in step 204.

  One effect of the system 1 according to the present invention is that if the patient has an irregular breathing pattern that suggests that the patient is awake and anxious, the pressure supplied to the patient is adjusted (eg, Reduce to zero value or a preset low level). The pressure is maintained or increased if breathing indicates regular (eg, suggesting sleeping) or breathing that causes sleep disturbances.

  It will be apparent to those skilled in the art that various modifications and variations can be made in the structure and methodology of the present invention without departing from the spirit or scope of the invention. Accordingly, the present invention is intended to embrace all such modifications and variations that fall within the scope of the appended claims and their equivalents.

Claims (18)

A positive airway pressure system for treating a sleep disorder in a patient,
A generator for supplying airflow to the patient's airway and applying pressure;
A sensor for measuring data corresponding to the patient's breathing pattern;
Analyzing the patient's breathing pattern, the detected breathing pattern is: (i) a state in which the patient is breathing regularly, (ii) a state of breathing in which the patient is experiencing sleep disturbances, (iii) a patient Is a REM sleep state, and (iv) a processing device that determines whether the patient exhibits one of an arousal state in which the patient feels discomfort and adjusts the pressure applied in correlation with the patient's state And
If the patient's breathing pattern indicates a state of (iv), the processor sets a target pressure value and controls the generator to adjust the applied pressure to approach the target pressure value A system characterized by The processing device transfers control of the generator to a therapeutic pressure regulator if a patient breathing pattern indicates one of the states (i), (ii), and (iii). The described system. When the target pressure value is reached, the processor applies the pressure until the patient's breathing pattern changes from the current state to one of the states (i), (ii) and (iii). The system of claim 1, wherein: is maintained at a target pressure value. The system according to claim 1, wherein the processing device adjusts a pressure applied so as to approach a target pressure value based on a predetermined increase amount. The system of claim 2, wherein the therapeutic pressure regulator controls the generator until a patient breathing pattern indicates the condition (iv). The system of claim 2, wherein the therapeutic pressure regulator automatically adjusts the applied pressure by performing a titration. When the patient's breathing pattern shows a change from one of the states (i), (ii) and (iii) to the state (iv), the processor adds the generator by controlling the generator The system of claim 1, wherein the pressure is reduced. When the patient's breathing pattern indicates a change from the state (iv) to one of the states (i), (ii) and (iii), the processing device controls the generator by the generator. The system of claim 2, wherein the pressure delivered is transferred to the therapeutic pressure regulator that increases. A system for monitoring patient breathing, comprising:
A sensor for measuring data corresponding to the patient's breathing pattern;
And a processing device for determining whether the patient's breathing pattern indicates an arousal state in which the patient feels uncomfortable. The system of claim 9, further comprising a patient interface coupled to the sensor for receiving patient airflow. The system of claim 9, further comprising a mask attached to the patient's face and covering at least one of the patient's mouth and nose. The system of claim 9, further comprising a tube for connecting the mask to the processing apparatus. The system of claim 9, further comprising a ventilator that prevents re-inhalation of the airflow discharged by the patient. The system of claim 9 further comprising a database for storing data. The processing device compares the data to data stored corresponding to a patient's previous breathing pattern to determine whether the patient breathing pattern indicates an arousal state in which the patient feels uncomfortable. Item 15. The system according to Item 14. The system of claim 9, wherein the processing unit determines whether the patient's breathing pattern indicates that the patient is taking regular breathing. The system of claim 16, wherein the processing device indicates when the patient's breathing pattern changes from a state of regular breathing to an arousal state of discomfort. The system of claim 9, wherein the processing device identifies at least one of apnea, hypopnea and repetitive obstructive apnea in a patient breathing pattern.

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